| ccdconfig.8 (7f3dea244c40159a41ab22da77a434d7c5b5e85a) | ccdconfig.8 (18252fc19288b5afbef646fffaf46153bae40f25) |
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| 1.\" $NetBSD: ccdconfig.8,v 1.1.2.1 1995/11/11 02:43:33 thorpej Exp $ 2.\" 3.\" Copyright (c) 1995 Jason R. Thorpe. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: --- 131 unchanged lines hidden (view full) --- 140.Pp 141The component devices need to name partitions of type 142.Li FS_BSDFFS 143(or 144.Dq 4.2BSD 145as shown by 146.Xr disklabel 8 ). 147.Sh EXAMPLE | 1.\" $NetBSD: ccdconfig.8,v 1.1.2.1 1995/11/11 02:43:33 thorpej Exp $ 2.\" 3.\" Copyright (c) 1995 Jason R. Thorpe. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: --- 131 unchanged lines hidden (view full) --- 140.Pp 141The component devices need to name partitions of type 142.Li FS_BSDFFS 143(or 144.Dq 4.2BSD 145as shown by 146.Xr disklabel 8 ). 147.Sh EXAMPLE |
| 148The following command, executed from the command line, would configure ccd0 149with 4 components (/dev/da2e, /dev/da3e, /dev/da4e, /dev/da5e), and an 150interleave factor of 32 blocks. 151.Bd -unfilled -offset indent 152# ccdconfig ccd0 32 0 /dev/da2e /dev/da3e /dev/da4e /dev/da5e | 148.Pp 149A number of ccdconfig examples are shown below. The arguments passed 150to ccdconfig are exactly the same as you might place in the 151.Pa /etc/ccd.conf 152configuration file. The first example creates a 4-disk stripe out of 153four scsi disk partitions. The stripe uses a 64 sector interleave. 154The second example is an example of a complex stripe/mirror combination. 155It reads as a two disk stripe of da2e and da3e which is mirrored 156to a two disk stripe of da4e and da5e. The last example is a simple 157mirror. /dev/da2e is mirrored with /dev/da4e and assigned to ccd0. 158.Pp 159.Bd -unfilled -offset 160# ccdconfig ccd0 64 none /dev/da2e /dev/da3e /dev/da4e /dev/da5e 161# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da3e /dev/da4e /dev/da5e 162# ccdconfig ccd0 128 CCDF_MIRROR /dev/da2e /dev/da4e |
| 153.Ed 154.Pp | 163.Ed 164.Pp |
| 165When you create a new ccd disk you generally want to 166.Nm disklabel 167it before doing anything else. Once you create the initial label you can 168edit it, adding additional partitions. The label itself takes up the first 16916 sectors of the ccd disk. If all you are doing is creating filesystems 170with newfs, you do not have to worry about this as newfs will skip the 171label area. However, if you intend to 172.Nm dd 173to or from a ccd partition it is usually a good idea to construct the 174partition such that it does not overlap the label area. For example, if 175you have A ccd disk with 10000 sectors you might create a 'd' partition 176with offset 16 and size 9984. 177.Pp 178.Bd -unfilled -offset 179# disklabel -r -w ccd0c auto 180# disklabel -e ccd0c 181.Ed 182.Pp 183The disklabeling of a ccd disk is usually a one-time affair. Unlike other 184devices, ccd currently requires that you specify partition 'c' when 185running disklabel. If you reboot the machine and reconfigure the ccd disk, 186the disklabel you 187had created before will still be there and not require reinitialization. 188Beware that changing any ccd parameters: interleave, flags, or the 189device list making up the ccd disk, will usually destroy any prior 190data on that ccd disk. If this occurs it is usually a good idea to 191reinitialize the label before [re]constructing your ccd disk. 192.Pp 193.Sh RECOVERY 194.Pp 195An error on a ccd disk is usually unrecoverable unless you are using the 196mirroring option. But mirroring has its own perils: It assumes that 197both copies of the data at any given sector are the same. This holds true 198until a write error occurs or until you replace either side of the mirror. 199.Nm Ccd 200uses a poor-man's mirroring implementation. It works well enough that if 201you begin to get disk errors you should be able to backup the ccd disk, 202replace the broken hardware, and then regenerate the ccd disk. If you need 203more then this you should look into external hardware RAID SCSI boxes, 204RAID controllers such as the 205.Nm dpt 206controller, or software RAID systems such as 207.Nm vinum . 208.Pp |
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| 155.Sh FILES 156.Bl -tag -width /etc/ccd.conf -compact 157.It Pa /etc/ccd.conf 158default ccd configuration file 159.El 160.Sh SEE ALSO 161.Xr ccd 4 , 162.Xr rc 8 | 209.Sh FILES 210.Bl -tag -width /etc/ccd.conf -compact 211.It Pa /etc/ccd.conf 212default ccd configuration file 213.El 214.Sh SEE ALSO 215.Xr ccd 4 , 216.Xr rc 8 |
| 217.Xr vinum 8 |
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| 163.Sh HISTORY 164The 165.Nm 166command first appeared in 167.Nx 1.0a . | 218.Sh HISTORY 219The 220.Nm 221command first appeared in 222.Nx 1.0a . |